A Mexican court has thrown out the conviction of infamous drug lord Rafael Caro Quintero, 28 years after he was convicted and imprisoned for the 1985 kidnapping and murder of U.S. DEA agent Enrique Camarena.

Quintero had been serving a 40-year sentence for torturing and killing Camarena, but the court voided the sentence on a technicality — saying he should have been tried in a state court instead of the federal court where he was convicted.

After the announcement of his release, Mexican television showed a graying Quintero, now 61, leaving a medium-security prison in the state of Jalisco, "where he reportedly had lived a life of semi-luxury," according to the Los Angeles Times.

The Times provides some background on the case:

"Special Agent Enrique 'Kiki' Camarena was working for the U.S. Drug Enforcement Administration, based in the city of Guadalajara, when Caro Quintero allegedly ordered him killed. Camarena went missing in February 1985, as he left the U.S. consulate. His body, showing evidence of torture, was eventually discovered near a ranch in western Mexico's Michoacan state, along with that of the Mexican pilot he flew with to hunt marijuana fields. ...

"The Camarena killing strained relations between Mexico and Washington. U.S. officials were furious at Mexican authorities and suspicious that there had been high-level cooperation with Caro Quintero and, at the minimum, a cover-up of the crime by what was supposedly a friendly government."

Mike Vigil, the former chief of international operations for the U.S. Drug Enforcement Administration, was quoted in The Houston Chronicle as calling the court's decision "egregious."

"The U.S. has got to exert pressure; 28 years is not enough for his crime." Vigil said.